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F. A. LUNDQUIST. AUTOMATIC TELEPHONE EXCHANGE.

APPLICATION FILED AUG.28, I916- Patented June 24, 1919.

3 SHEETSSHEET [4 F. A. LUNDOUIST. AUTOMATIC TELEPHONE EXCHANGE.

' APPLICATION FILED AUG-2B. 1915. I 1,307,589. Patented June 24,1919.

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AUTOMATIC TELEPHONE EXCHANGE. APPLICATION. FILED AUG-28.1916. 1,307,589, Patented June 24,1919

3 SHEETSSHEET EaV WW W

WW WW UNITED STATES PATENT OFFICE.

FRANK A. LUNDQUIST, OF NEW YORK, N. Y., ASSIGN'OR T CASPER L. REDFIELD, TRUSTEE, OF CHICAGO, ILLINOIS. I

AUTOMATIC TELEPHONE-EXCHANGE.

Specification of Letters Patent. Patented June 24, 1919.-

Application filed'August 28, 1916. Serial No. 117,168.

To all whom it may concern:

Be it known that I, FRANK A. LUND UIST, a citizen of the United States of America, and a resident of .New York, county of N. Y., and State of New York,'hav e invented new and useful Improvements in Automatic nections step by step from one set of linesto another to build up a talking circuitbetween local stations. 1

In such exchanges, each subscriber has,

. at his local station, a calling device, orcertain contact making devices, bythe operation of which impulses are sent to operate magnets at the central oflice. Such devices are well known and consequently are not herein shown or described. It will simply be. assumed-that the calling subscriber oper-.

ates his devices to send the impulses hereinafter referred to. cally moving pieces or parts and the circuits over which such magnets are operated by impulses sent directly or indirectly as the result of the calling subscriber closing contacts at his local station are also well known and need no description. Someof the magnets and circuits therefor are omitted in the present drawings and description as they involve nothing different from what is in common use, or is illustrated in many patents relating to automatic telephone exchanges. In some cases I have simply shown the part to be moved, leaving the magnet connections to be made in any convenient manner. In the accompanying drawings Figure 1 is a diagram showing one local station and a part of the'primary apparatus at the central oflice; v

Fig. 2 is a diagram of a part of the secondary apparatus at the central oflice;

Fig. 3 is an elevation of part of the apparatus, the same being a view on line 33 of Fig. 2, and thestructure being partly dia-.

grammatic;

- Fig. 4 is a side elevation of a part of Fig. 8; and Fig. 5 is a plan, beinga sectionjon line 55 of Fig. 3.

Further illustration and description of Magnets for mechanithe type of exchange herein set forth may I be found in my Patent No. 1,264,826, issued April 30, 1918.

Supported in the upper part of the room in which is located the central office apparatus is a continually running shaft 10 on which are loosely mounted a series of sheaves 11 Springs 12 secured to the shaft act to push the sheaves longitudinally on the shaft into engagement with a clutch member 13 pinned to that shaft. For each sheave there is a lever 14 pivoted at 15. An armature lever 16 has a hooked end 17 for engaging pins on the lower ends of each lever 14. The arrangement/is such that the parts just described act to force their adjacent sheaves 11 away from the clutch members 13.

When, however, a magnet 71 acts to attract its armature lever 16,, the hook 17 is released and the spring 12 forces the corresponding sheave 11 into engagement with the driving clutch member 13. p I Located below each sheave 11 is a pair of guide wires 18, and upon each pair is a drop 19 connected to a corresponding sheave 11 by a cord 20. When a sheave is driven by the shaft 10 it acts to elevate its drop 19 until a-projection 21 'on said drop engages the corresponding lever 14 to' push the sheave out of engagement with its driving member. When this occurs a catch on an armature lever 22 serves to support the drop at its elevated position until released as will be hereinafter described.

Pivoted on each drop 19 is a depending arm 23 having a fork 24 on itslower end, and carrying a piece of insulation 25 adapted .to engage and close suitably supported elec trical contacts when said arm is swung outward on its pivot.

elevated position. When the fork 24 of a falling drop engages a pin 27 it causes a partial rotation of the shaft 26. I I

On theend of each shaft 26 is a piston 28 fitting into a cylinder 29 provided with connections to a source of compressed air 30.

In the connections between each cylinder 29 and the source 30 is avalve mechanism 31 controllable by a bell crank lever 32 and rod 33. On each shaft 26 is a pin 34 adapted to engage the bell crank 32 and operate the valve 31 whenever a shaft is rotated by a falling drop 19. Normally, the valve 31 closes the connection between the cylinder 29 and the compressed air 30, and opens the connection between the cylinder and the outside air. When the rotation of the shaft 26 causes pin 34 to engage bell-crank 32, the valve is shifted so as to open the connection to the source and to close the exhaust. Under these conditions the compressed air enters the cylinder 29 behind the piston 28 and forces said piston and shaft 26 to the left. Because the fork 24 of arm 23 is in engagement with a pin 27 ,this movement carries said arm to the left and causes insulation 25 to engage and close adjacent electrical contacts as shown at the left in Fig. 1. Two of these contacts are connected to the local station associated with the particular dropv which caused the operation, and the other two are connected with lines leading to the secondary apparatus shown in Fig. 2.

It will be seen from the foregoing that the weight of a drop falling upon a pin 27 causes a partial turning of a shaft 26, and that this turnin action releases power which moves the sha longitudinally and closes contacts which extend local station connections on to secondary apparatus. The longitudinal movement of the shaft carries its other pins 27 out of the paths of 'theforks 24 on other drops, so that if another drop should fall it would pass any moved shaft and engage a pin on the first shaft 26 which it found in normal position. In other words, the apparatus is an automatic trunk selecting apparatus by which the line extending to the local station is extended in the central oflice to secondary apparatus.

When the drop is lifted from a pin 27, the moved shaft 26 returns to normal osition. A spring may be-used to rotate t e. shaft back to normal, or it may be moved back by power. As shown in Fig. 1 the valve 31 is arranged so that the pressure of air normally acts upon the valve to shift it in the opposite direction to that by the weight of the drop. Consequently, when the drop is lifted the valve is automatically moved to rotate the shaft, and to close the port between the supply 30 and the cylinder 29, and at the same time opening the exhaust from the cylinder. then moves the shaft longitudin its normal position.

The secondary apparatus, 2, 3, 4, and 5, differs from the rimary apparatus only in details. To avoi duplications, ,the elevating apparatus associated with shaft 10, and theower apparatus associated with shown in Figs.

in which it was moved A spring 35 ally back to the air supply 30, are not shown in connection with the secondary apparatus. It is to be understood, however, that the same or similar construction is used for both. The main difference between the two is that the primary apparatus simply selects an idletrunk out of one group of trunks, whereas the secondary apparatus is used for the preliminary selection of a desired group of trunks and then to automatically select an idle trunk from the previously selected group.

The drop 36 has a depending arm having branches 37 and 38. The-branch 37 has a piece of insulation 39 arranged to close electrical contacts as in the case of insulation 25 on arm 23. On branch 38 there is hingeda secondary arm 40 having a fork. 41 for engaging pins 42 on shaft 43. These shafts and pins are the same as those before described, and are connected to the same power source in the same Way. 1

is used for the selection of that group. And

so on.

On the upper end of the shaft 45 is a ratchet wheel 47 having teeth to correspond to the projections 46. When the ratchet wheel is advanced one step, by a magnet or otherwise, the first projection 46 comes in the path of a branch arm 48 on the hinged arm 40. When the ratchet wheel is advanced two steps the second projection 46 is in the path of arm 48, and so on. The first step of the ratchet wheel is preferably a half step so that in normal position the shaft 45 and arm 48 will have the relationship shown in Fig. 5. All other steps are full steps.

On the drop 36 is a; latch 49 and on the shaft 45 is a pin 50 adapted, when the shaft isin normal position, latch to support the drop 36 at its elevated position. The first step, however, of the ratchet wheel 47 moves the pin 50 from under the latch 49. and permits the drop to fall. -The shafts .43 and their pins 42 are so arranged that, unless a projection 46 is in the path of the arm 48, the forked arm 40 will pass clear of the pins 42 when the drop 36 falls. Thus, if the ratchet wheel 47 should be advanced six steps from normal,

the arm 48 would pass five projections 46 and engage the sixth one. In so doing the.

to be engaged by the will engage the first pin 42 it finds in normal position. It is to be understood that there is one shaft 43- for each set of trunk terminals closed by the insulation 39, and that these shafts are divided into groups correspond ing to the groups of terminals.

When the arm 48 engages a projection 46, the arm 40 is moved outward on its hinge to cause the fork 41 to engage a pin 42 and thus turn a shaft 43. The shafts 43 are provided with the same power appliances as shafts 26; consequently the turning of. shaft 43 brings about its longitudinal movement to swing arm 37 on its pivot and cause insulation 39 to close electrical connections or trunk terminals.

One local station is represented at A as having a ground connection, and wires 51 and 52 leading to the central jofiice.

Branches 53 and 54 lead to fixed contactsprings associated with the upper shaft 26. Adjacent to these fixed contacts are flexible contact springs which form local terminals for the trunk wires 55 and 56, which trunk wires extend to the secondary apparatus and at which place they have a series of trunk terminals as shown in Fig. 2. The

station Wires 51 and 52 also have branches 57 and 58 leading to fixed contacts, and as sociated with these fixed contacts for the trunks 59 and 60 which also extend to the secondary apparatus. Similarly, 51 and 52 have other extensions to the secondary apparatus through 61, 62, 63 and 64, and so on. A group of one hundred (more orless) local stations like A have drops like 19, each one of which upon being released automatically connects its stations wires to an idle one of a group of ten (more or less) trunks like 5556. A second similar group of local stations have drops which similarly serve to connect to an idle trunk in a second group represented by B in Fig. 2. A third group of local stations in the same way connect to a third group of trunks C, and so on. Each trunk, as 5556, has a drop 36 and associated parts, which drop in falling can automatically Epick out an idle trunk in any group as D, F, etc. If the shaft 45, in moving to release drop 36, moves only one step, then the drop will take the first idle trunk in group D. If the shaft 45 moves two steps, then the drop will take a trunk in group E, and so on. I

The manner in which station wires 51.-52 are connected to the trunk wires 5556 represents the manner in which drop 36 connects the trunk wires 5556 to other trunk wires 6566. The trunk wires 6566 may connect directly with the connector switches of an ordinary type, or the may be-associated with another drop li e 36, and this drop may operate in the same way to exto connector SWifiCheS,

In operation the subscriber at a local station, as A, closes electrical connection between ground and the line 51, when a current flows: ground5167magnet M- 68-battery Xground. This actuates magnet M to move armature 22 and release his drop 19. When the forked arm 23 on the falling drop finds a pin 27 in its path, the fall of the drop is arrested and the shaft 26 is turned. The turning of the shaft acts through pin 34 and bell crank 32 to shift valve 31 and permit compressed air to enter behind piston 28. This moves the shaft to the left, carrying arm 23 with it and causing insulation 25 to engage and close the line terminals which it finds in its path when so moved. This connects the station line 51- 52 to. the trunk 5556, withwhich trunk is associated the drop 36 and shaft 45.

The subscriber then closes electrical contacts at his. station one or more times as desired for the purpose of sending impulses over line 5152 and 5556 to a magnet arranged to rotate ratchet wheel 47. The magnet and its electrical connections for this are not shown as ways for operating such magnets are well known in the art, and have been described by me and by others in many issued patents. If the subscriber wants connections through the first group, he closes the electrical contacts only once. If the connection wanted is in the second group, he closes the contacts twice; if in the third group he closes them three times; and so on.

Upon the first movement of the ratchet wheel 47, the pin 50 slips from under the latch 49 and the drop 36 falls. Assuming that the calling subscriber at station A Wanted connection in the fifth group, there would 'be five steps of the ratchet wheel 47 and shaft 45 would stop with the fifth projection 46 in the path of arm 48 of the falling drop 36. When the falling drop reaches the position at which arm 48 engages the projection 46 in its path, the arm 40 is moved laterally outward on its hinge and its fork 41 engages the first pin 42 on shaft 43 which it finds in normal position. When this occurs, the shaft 43 is first turned and then moved longitudinally to carry the pin 42 out of normal position and move arm 37 so that insulation will engage and close the contacts in the path. This connects trunks 5556 to a trunk in the fifth group corresponding to the trunk 65-66 shown in Fig. 2. From this point the selection then proceeds in a similar manner for another stage, if there is such a stage. If not, then the connector switch is operated in the ordinary manner. The question of whether there is or not another stage depends upon the size of the exchange and not at all upon the manner of operation.

From theforegoing descrlption it will be seen that each subscribers line, consisting of two wires, crosses a series of trunks, each also consisting of two wires. At each crossing point both the line and the trunks are provided with contact terminals adjacent to each other but out of actual contact .with each other. Each subscriber has associated with his line a drop which may be released and in falling will connect some automatically selected terminals of the line'with the adjacent terminals of an idle trunk so that the trunk itself becomes an extension of the line. Furthermore, a group, of 'su bscribers lines cross a group'of trunks there being contact terminals for all crossing points so that any subscribers line may be connected to any trunk, and any trunk may receive connections from any su'bscribers line.

When a connection is so made, the selected trunk becomes an extension of the subscribers line. In the next stage all of the extensions of a group cross a plurality of groups of other trunks,-there being sinnlar contact terminals for both extensions and trunks at all points where extensions and trunks cross each other.' Associated with each extension is a drop which, upon falling, will connect the extension to some automatically selected trunk in a-previously selected group. The drop is released and the group selected by the subscriber which happensyat the time to have the extension as part of his line. Whena connection is so made between an extension and atrunk in this second stage operation, the second trunk then'becomes a second extension to the subscribers line.

The next stage of operations is either a repetition of the second stage or the ordinary operation of a connector switch. Neither of these things need further description.

Returning now to the primary apparatus, there are, associated with each drop 19, contacts 76 and 69 which are held open by the drop when it is in its elevated position but which close when the drop falls. Associated. with the magent M are contacts 73 and 74 which are normally open but which are closed by the action of said magnet. In restoring the apparatus to normal position, the calling subscriber at station A connects both 51 and 52 to ground, whereupon a current flows: ground 5167-'M-68X- ground. This closes contacts 73 and 74 whereupon another current flows: round 527669-707172.737 4 568 Xground.

The impulse through magnet 71 moves the leverv 16 to release-hook 17 from the pins on lever 14:. The spring 12 then pushes the sheave 11 into engagement with the clutch member 13, and the rotation of shaft 10 and sheave 11 wind up the cord 20 and raise the drop 19. At its uppermost position, the

drop 19 engages spring 68 to open connec- 14 to turn it on its pivot 15 and push sheave 11 from engagement with clutch member 13.

In this action the hook 17 again engages the pins on lever '11 to hold it in the position shown in the drawing. \Vhen the drop is lifted from pin 27 the shaft '26 is returned to normal position in the manner previously described. The catch on lever .22 also slips under and supports the drop at its elevated and trunksat the crossing points, a deviceassociated with each line and movable along a path parallel to the line, a shaft associated with each trunk and having-projections normally supported in the paths of said devices, and means by-which upon a device engaginga projection in its path both device and shaft will be moved to close the terminals at the crossing which corresponds to device and shaft.

2. The combination with a series of lines, a series of trunks crossing the lines, and Contact terminals for lines and trunks at the crossing points, of a movable line device for each line, a movable trunk device for each Ition with contact 69, and also engages lever trunk, and means by which upon engagement between a line device and a trunk device each will movethe other from normal position to close the contact terminals between associated line and associated trunk.

3. .The combination with a series of subscribers lines, a series of trunks crossing the lines, and contact terminals for lines and trunks at the crossing points, of a device associated with each line and movable to automatically select an idle trunk and means by which upon 2. moved device making such a selection said device will be further moved automatically toclose the term} nals at the crossing point of line and selected trunk.

4. The combination with a series of subscribers llnes, a serles of trunks crossmg the lines, and Contact terminals for lines and trunks at the crossing points, of a de-' vice associated with each line and movable I along the line to automatically select an idle trunk, and means associated with the trunk so selected for moving said device laterally to close the contact terminals at the crossing point corresponding to said line and said trunk.

5. The combination with the stations of a telephone exchange, lines leading from the stations to a central oflice, and a plurality of trunks crossing the lines, of contact terminals onlines and trunks at crossing points, power mechanism for closing adjacent terminals to connect lines and trunks, and a movable device associated with each line and arranged to release the power mechanism to cause such connection.

6. The combination with the stations of a telephone exchange, lines extending from the stations to a central office, trunks located 1 at the central office and each having contact terminals for each of said lines, and other contact terminals on each line adjacent to a contact terminal on each trunk, of a movable device associated with each line, a power device having projections in the path of each movable device, and means by which upon a movable device engaging one of said projections the power device will close the contact terminals which connect the associated line and terminal witheach other.

7. The combination with the lines and trunks of a telephone exchange, and contact terminals on each line for all trunks and on each trunk for all lines, of a movable member associated with each line and controlled by electrical impulses thereover, a power device controlled by the movable members, and means by which the movable members and the power device serve to extend telephonic connections from the'lines to the trunks by closing contact terminals between lines and trunks.

8. The combination with the lines and trunks of a telephone exchange, and contact terminals on each line for all trunks and on each trunk for all lines, said terminals on the lines being adjacent to the terminals on the trunks, of means associated with each line for automatically selecting an idle trunk, and power mechanism for closing the terminals between the associated line and a trunk so selected.

'9. The combination with the lines and trunks of a telephone exchange, and contact terminals by which any line may be connected to any trunk, of a movable body, an obstruction in the path of said body, and power mechanism set into operation to connect a line to a trunk when said body engages said obstruction.

when falling, and means by which upon a falling drop engaging a rod said rod will be moved from the paths of other falling drops and the line associated with the falling drop will be connected to the trunk associated body, an arm pivoted thereon, a piece of insulating material carried by the arm, a series of obstructions in the path of the arm when the body moves, a corresponding series of electrical terminals adjacent to the path of the insulating material, and means by which an engagement of the arm with an obstruction will move said arm on its pivot and cause the insulatingmaterial to engage and close the corresponding termina s.

13. Ina telephone exchange, a series of drops, an arm pivoted to each drop, insulating material carried on each arm, a series of rods each of which has a projection or partin the paths of the arms when the drops fall, contact terminals corresponding to the proj ections, and means by which an engagement of an arm with an obstruction will move the arm on its pivot to cause the insulating material carried thereby to engage and close the terminals corresponding to the projectionengaged by the arm.

14. In a telephone exchange, a series of 4 drops, a series of rods each of which has a projection in the path of a part of each drop when falling, contact terminals corresponding to the projections, and means by which an engagement between a part and a projec-. tion will move the part to close the terminals corresponding to the engaged projection.

'15. In a telephone exchange, a series of drops, aseries of rods each having a PI'OjGC-r tion in the path of a part of each drop, contact terminals corresponding to the projections, and means by which an engagement between a part and a projection will move the part to close the terminals corresponding to the engaged projection and will also move the rod to remove its other projections from the paths of other drops.

FRANK A. LUNDQUIST. 

